(精华)2020年8月22日 微服务 Consul负载均衡策略(.net core版)

#region 调用---负载均衡
{
    //string url = "http://localhost:5726/api/users/get";
    //string url = "http://localhost:5727/api/users/get";
    //string url = "http://localhost:5728/api/users/get";
    string url = "http://{域名}/api/users/get";
    //consul解决使用服务名字 转换IP:Port----DNS

    Uri uri = new Uri(url);
    string groupName = uri.Host;
    using (ConsulClient client = new ConsulClient(c =>
    {
        c.Address = new Uri("http://localhost:8500/");
        c.Datacenter = "dc1";
    }))
    {
        var dictionary = client.Agent.Services().Result.Response;
        var list = dictionary.Where(k => k.Value.Service.Equals(groupName, StringComparison.OrdinalIgnoreCase));//获取consul上全部对应服务实例
        KeyValuePair<string, AgentService> keyValuePair = new KeyValuePair<string, AgentService>();
        //拿到3个地址，只需要从中选择---可以在这里做负载均衡--
        //{
        //    keyValuePair = list.First();//直接拿的第一个
        //}
        //{
        //    var array = list.ToArray();
        //    //随机策略---平均策略
        //    keyValuePair = array[new Random(iSeed++).Next(0, array.Length)];
        //}
        //{
        //    var array = list.ToArray();
        //    //轮询策略---平均策略
        //    keyValuePair = array[iSeed++ % array.Length];
        //}
        {
            //权重---注册服务时指定权重，分配时获取权重并以此为依据
            List<KeyValuePair<string, AgentService>> pairsList = new List<KeyValuePair<string, AgentService>>();
            foreach (var pair in list)
            {
                int count = int.Parse(pair.Value.Tags?[0]);
                for (int i = 0; i < count; i++)
                {
                    pairsList.Add(pair);
                }
            }
            keyValuePair = pairsList.ToArray()[new Random(iSeed++).Next(0, pairsList.Count())];
        }
        resultUrl = $"{uri.Scheme}://{keyValuePair.Value.Address}:{keyValuePair.Value.Port}{uri.PathAndQuery}";
        string result = WebApiHelperExtend.InvokeApi(resultUrl);
        userList = Newtonsoft.Json.JsonConvert.DeserializeObject<List<Users>>(result);
    }
}
#endregion